Offline Country or Place Locator

Detects country or place/city by a given geometry.

Installation

npm install offline-country-or-place-locator

Why

Main idea behind this fork is the freedom to have any custom data set as per your requirements. Hence this package doesn't include a data set unlike the original package which included a some 20MB data set of countries. This enables this package to be used in places like react native mobile app and more without the worry of adding extra space.

Where to get the data set

This approach enables the data set to vary depedning on your requirments. For example You can download data sets from:

countries.geojson from geo-countries.
cities.geojson from geojson-world-cities.

Custom data set

Or you can create your own custom data set from tools like:

geojson.io

Usage

findPlaceByCoordinate accepts geoJson data set, latitude & longitude, or a point as an array,
and returns the Feature object with the following fields:

type: GeoJson type
properties: this is where you'll find all the useful information about the country/city/place depending on the data set you input
geometry: this is where you'll find the coordinates

import {findPlaceByCoordinate} from "offline-country-or-place-locator";

try{
    const countryInfo = findPlaceByCoordinate(yourCountriesGeoJson, 51.500760, -0.125168);
    
    // assuming your data set has united kingdom and the properties
    // object has "ADMIN" key which stores the country name and
    // the "ISO_A3" key which stores the country code.
    // note these keys could change depending on your data set
    console.log(countryInfo.properties.ADMIN); // United Kingdom
    console.log(countryInfo.properties.ISO_A3); // GBR 
} catch (error){
    console.error(error);
}

You can also call it as a point - an array of [x, y]
PAY ATTENTION - x == longitude and y == latitude

try{
    const countryInfo = findPlaceByCoordinate(yourCountriesGeoJson, [-0.125168, 51.500760]);
    
    console.log(countryInfo.properties.ADMIN); // United Kingdom
    console.log(countryInfo.properties.ISO_A3); // GBR 
} catch (error){
    console.error(error);
}

findPlacesByPolygon accepts a polygon (array of points arrays)
and returns an array of Feature Objects which contains the details of the countries/cities/places (depends on your dataset) that intersect with a given polygon

import {findPlacesByPolygon} from "offline-country-or-place-locator";

try{
    const results = findPlacesByPolygon(yourGeoJson,[
        [-131.484375, 49.781264058178344],
        [-137.548828125, 44.15068115978094],
        [-128.935546875, 26.194876675795218],
        [-96.240234375, 22.755920681486405],
        [-72.50976562499999, 26.43122806450644],
        [-59.501953125, 42.48830197960227],
        [-62.314453125, 48.3416461723746],
        [-76.2890625, 50.3454604086048],
        [-109.77539062499999, 53.173119202640635],
        [-131.484375, 49.781264058178344]
    ]);
    console.log(results);
} catch (error){
    console.error(error);
}

Test

npm run test

License

Offline Country or Place Locator is MIT licensed.

ali-thowfeek / offline-country-or-place-locator Goto Github PK